Relands 165c583d57
[VM] Introduction of type testing stubs - Part 1
This CL:
* Adds a field to [RawAbstractType] which will always hold a pointer
to the entrypoint of a type testing stub
* Makes this new field be initialized to a default stub whenever a
instances are created (e.g. via Type::New(), snapshot reader, ...)
* Makes the clustered snapshotter write a reference to the
corresponding [RawInstructions] object when writing the field and do
the reverse when reading it.
* Makes us call the type testing stub for performing assert-assignable
checks.
To reduce unnecessary loads on callsites, we store the entrypoint of the
type testing stubs directly in the type objects. This means that the
caller of type testing stubs can simply branch there without populating
a code object first. This also means that the type testing stubs
themselves have no access to a pool and we therefore also don't hold on
to the [Code] object, only the [Instruction] object is necessary.
The type testing stubs do not setup a frame themselves and also have no
safepoint. In the case when the type testing stubs could not determine
a positive answer they will tail-call a general-purpose stub.
The general-purpose stub sets up a stub frame, tries to consult a
[SubtypeTestCache] and bails out to runtime if this was unsuccessful.
This CL is just the the first, for ease of reviewing. The actual
type-specialized type testing stubs will be generated in later CLs.
Reviewed-on: https://dart-review.googlesource.com/44787
Relands f226c22424
[VM] Introduction of type testing stubs - Part 2
This CL starts building type testing stubs specialzed for [Type] objects
we test against.
More specifically, it adds support for:
* Handling obvious fast cases on the call sites (while still having a
call to stub for negative case)
* Handling type tests against type parameters, by loading the value
of the type parameter on the call sites and invoking it's type testing stub.
* Specialzed type testing stubs for instantiated types where we can
do [CidRange]-based subtype-checks.
==> e.g. String/List<dynamic>
* Specialzed type testing stubs for instantiated types where we can
do [CidRange]-based subclass-checks for the class and
[CidRange]-based subtype-checks for the type arguments.
==> e.g. Widget<State>, where we know [Widget] is only extended and not
implemented.
* Specialzed type testing stubs for certain non-instantiated types where we
can do [CidRange]-based subclass-checks for the class and
[CidRange]-based subtype-checks for the instantiated type arguments and
cid based comparisons for type parameters. (Note that this fast-case migth
result in some false-negatives!)
==> e.g. _HashMapEntry<K, V>, where we know [_HashMapEntry] is only
extended and not implemented.
This optimizes cases where the caller uses `new HashMap<A, B>()` and only
uses `A` and `B` as key/values (and not subclasses of it). The false-negative
can occur when subtypes of A or B are used. In such cases we fall back to the
[SubtypeTestCache]-based imlementation.
Reviewed-on: https://dart-review.googlesource.com/44788
Relands 25f98bcc75
[VM] Introduction of type testing stubs - Part 3
The changes include:
* Make AssertAssignableInstr no longer have a call-summary, which
helps methods with several parameter checks by not having to
re-load/re-initialize type arguments registers
* Lazily create SubtypeTestCaches: We already go to runtime to warm up
the caches, so we now also create the caches on the first runtime
call and patch the pool entries.
* No longer load the destination name into a register: We only need
the name when we throw an exception, so it is not on the hot path.
Instead we let the runtime look at the call site, decoding a pool
index from the instructions stream. The destination name will be
available in the pool, at a consecutive index to the subtype cache.
* Remove the fall-through to N=1 case for probing subtypeing tests,
since those will always be handled by the optimized stubs.
* Do not generate optimized stubs for FutureOr<T> (so far it just
falled-through to TTS). We can make optimzed version of that later,
but it requires special subtyping rules.
* Local code quality improvement in the type-testing-stubs: Avoid
extra jump at last case of cid-class-range checks.
There are still a number of optimization opportunities we can do in
future changes.
Reviewed-on: https://dart-review.googlesource.com/46984
Relands 2c52480ec8
[VM] Introduction of type testing stubs - Part 4
In order to avoid generating type testing stubs for too many types in
the system - and thereby potentially cause an increase in code size -
this change introduces a smarter way to decide for which types we should
generate optimized type testing stubs.
The precompiler creates a [TypeUsageInfo] which we use to collect
information. More specifically:
a) We collect the destination types for all type checks we emit
(we do this inside AssertAssignableInstr::EmitNativeCode).
-> These are types we might want to generate optimized type testing
stubs for.
b) We collect type argument vectors used in instance creations (we do
this inside AllocateObjectInstr::EmitNativeCode) and keep a set of
of used type argument vectors for each class.
After the precompiler has finished compiling normal code we scan the set
of destination types collected in a) for uninstantiated types (or more
specifically, type parameter types).
We then propagate the type argument vectors used on object allocation sites,
which were collected in b), in order to find out what kind of types are flowing
into those type parameters.
This allows us to extend the set of types which we test against, by
adding the types that flow into type parameters.
We use this final augmented set of destination types as a "filter" when
making the decision whether to generate an optimized type testing stub
for a given type.
Reviewed-on: https://dart-review.googlesource.com/48640
Issue https://github.com/dart-lang/sdk/issues/32603
Change-Id: I44a1d5d4b27454ae026aef2a301aada3dd399ea0
Reviewed-on: https://dart-review.googlesource.com/49861
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
In order to avoid generating type testing stubs for too many types in
the system - and thereby potentially cause an increase in code size -
this change introduces a smarter way to decide for which types we should
generate optimized type testing stubs.
The precompiler creates a [TypeUsageInfo] which we use to collect
information. More specifically:
a) We collect the destination types for all type checks we emit
(we do this inside AssertAssignableInstr::EmitNativeCode).
-> These are types we might want to generate optimized type testing
stubs for.
b) We collect type argument vectors used in instance creations (we do
this inside AllocateObjectInstr::EmitNativeCode) and keep a set of
of used type argument vectors for each class.
After the precompiler has finished compiling normal code we scan the set
of destination types collected in a) for uninstantiated types (or more
specifically, type parameter types).
We then propagate the type argument vectors used on object allocation sites,
which were collected in b), in order to find out what kind of types are flowing
into those type parameters.
This allows us to extend the set of types which we test against, by
adding the types that flow into type parameters.
We use this final augmented set of destination types as a "filter" when
making the decision whether to generate an optimized type testing stub
for a given type.
Issue https://github.com/dart-lang/sdk/issues/32603
Measured impact on flutter HEAD-HEAD-HEAD with TTS Part 1 - 4 applied (2018-04-03):
* stock build benchmark: around 4% improvement
* gallery app.so size: -2.68% (13987348 -> 13612928)
* gallery memory: no sigificant changes:
- SubtypeTestCache: - 10kb
- ObjectPool: + 6 kb
- Type: no change (probably due to wasted alignment slot before)
- TypeParameter: + 4 kb (can get rid of the field here later)
* gallery AOT compile-time: measured +1.3%, inside flakiness range
Change-Id: I12a398d18f970ba2db741913bb47b0f36ae38d58
Reviewed-on: https://dart-review.googlesource.com/48640
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
When the type to test against is instantiated and has no type arguments
there is a high probability that we receive instances of that class or
subclasses at runtime.
This CL therefore extends the fast-path of AssertAssignable/InstanceOf
by checking whether the instance class id is within the cid ranges that
directly/indirectly implement/extend the type to test against.
Currently we have an almost depth-first preorder numbering of class ids
in AOT, but there are exceptions. So each class can have a number of
cid-ranges as subclasses / classes which implement it's interface.
This seems to improve performance of dart-aot-v2
* flutter stock build by 15+%
* DeltaBlueClosures by 10+%
and reduces code size on
* flutter gallery by -3%
Issue https://github.com/dart-lang/sdk/issues/31798
Change-Id: I07dd91589cc3fcd8c5952bdba339e2e2a459e08e
Reviewed-on: https://dart-review.googlesource.com/35620
Commit-Queue: Martin Kustermann <kustermann@google.com>
Reviewed-by: Régis Crelier <regis@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
The safestack stack pointer is cached when invoking Dart code, and
manually restored when jumping over C++ frames for Dart exceptions
in Exceptions::JumpToFrame().
fixes#31356
Change-Id: I71c2e86d1d4f24571dd618a5db06fd1277339ebc
Reviewed-on: https://dart-review.googlesource.com/23141
Commit-Queue: Zach Anderson <zra@google.com>
Reviewed-by: Vyacheslav Egorov <vegorov@google.com>
This reverts commit af251ddfec.
Reason for revert: Crashes on Windows.
Original change's description:
> [vm] Prefer stack bounds from the system thread library for overflow checks.
>
> Before this change, we would assume all stacks have the size the VM specifies for threads it creates, but this won't be accurate for the initial thread or threads created by the embedder.
>
> Change-Id: I6605a88d6666a6f9d47fbe047d3fdd02aa22c80a
> Reviewed-on: https://dart-review.googlesource.com/10209
> Reviewed-by: Zach Anderson <zra@google.com>
TBR=rmacnak@google.com,zra@google.com
Change-Id: I96eaccdc8edf6e3d319827a63d168534bad0518e
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://dart-review.googlesource.com/13106
Reviewed-by: Ryan Macnak <rmacnak@google.com>
Before this change, we would assume all stacks have the size the VM specifies for threads it creates, but this won't be accurate for the initial thread or threads created by the embedder.
Change-Id: I6605a88d6666a6f9d47fbe047d3fdd02aa22c80a
Reviewed-on: https://dart-review.googlesource.com/10209
Reviewed-by: Zach Anderson <zra@google.com>
This is the first step to adding Thread Local Allocation Buffers to
the VM.
In this step, the mutator alone allocates to the new space, but keeps
track of the start and end of the space. This is akin to a single large
TLAB.
As a result, the generated code and the dbc simulator changed how they
allocate objects into the new space as well.
R=rmacnak@google.com
Review-Url: https://codereview.chromium.org/2980033002 .
This is the first step to adding Thread Local Allocation Buffers to
the VM.
In this step, the mutator alone allocates to the new space, but keeps
track of the start and end of the space. This is akin to a single large
TLAB.
BUG=
R=rmacnak@google.com
Review-Url: https://codereview.chromium.org/2951333002 .
The assertions which tried to assert that we only use
StackFrameIterator to walk frames of the current thread was incorrect.
We already have cases where other threads will walk the stack of the
mutator thread, see below for an example where this can happen.
Thread::VisitObjectPointers was incorrectly passing Thread::Current() to
the StackFrameIterator instead of 'this'. (Code in thread_registry.cc will
loop over a number of threads and calls VisitObjectPointers on them)
Mutator thread:
0 pthread_cond_wait@@GLIBC_2.3.2
1 dart::Monitor::WaitMicros
2 dart::Monitor::Wait
3 dart::MonitorLocker::Wait
4 dart::ThreadBarrier::Sync
5 dart::GCMarker::MarkObjects
6 dart::PageSpace::MarkSweep
7 dart::Heap::CollectOldSpaceGarbage
8 dart::Heap::CollectNewSpaceGarbage
9 dart::Heap::CollectGarbage
10 dart::DN_HelperObject_<native>
11 dart::BootstrapNatives::<native>
<dart frames>
MarkTask thread:
1 dart::EntryFrame::VisitObjectPointers
2 dart::Thread::VisitObjectPointers <---- Walks mutator thread stack
3 dart::ThreadRegistry::VisitObjectPointers <---- Iterates over a number of threads
4 dart::Isolate::VisitStackPointers
5 dart::Isolate::VisitObjectPointers
6 dart::GCMarker::IterateRoots
7 dart::MarkTask::Run
8 dart::ThreadPool::Worker::Loop
9 dart::ThreadPool::Worker::Main
10 dart::ThreadStart
R=rmacnak@google.com
Review-Url: https://codereview.chromium.org/2845053003 .
This CL improves the stack traces that accompany exceptions. Whenever an
async function is entered, we remember how we got there. This is similar
in spirit to package:stack_trace but the implementation is more efficient
and memory usage can be more easily reasoned about.
Tracking causal stack traces:
- [x] Upon entry to an async function, capture the synchronous stack trace prefix and store it into the closure.
- [x] Upon entry to an async* function, capture the synchronous stack trace prefix and store it into the closure.
- [x] Before returning from an async function, clear the Thread's asynchronous stack trace.
- [x] After resuming an async function, load the sychronous stack trace prefix into the Thread.
- [x] Filter stack traces to remove async machinery.
Service protocol changes:
- [x] Send causal async stack trace.
Observatory changes:
- [x] Display causal async stack trace below async functions.
Fixes https://github.com/dart-lang/sdk/issues/27661R=asiva@google.com, rmacnak@google.com
Comparisons: https://docs.google.com/a/google.com/document/d/10r6jEqr8OCiDZ4y9SYU_uOimcHiOGAZMly2ghTErALI/edit?usp=sharing
Review-Url: https://codereview.chromium.org/2646443005 .
This is a fixed version of c84f30741c90d040254767ff769a40d2cba3fb1a that
resolves issues with comparing uint and intptr_t.
Original Commit Message:
Added tracking of memory usage inside of threads. In addition, the max memory usage is kept track of using a high watermark for both the threads and the isolates. Isolate high watermark information is updated when a thread exits the isolate. The isolate high watermark consists of the sum of all thread high watermarks (including the high watermark of the exiting thread). High watermark information for both threads and isolates is now visible in the isolate view in the Observatory.
BUG=
R=johnmccutchan@google.com
Review-Url: https://codereview.chromium.org/2610253002 .
Added tracking of memory usage inside of threads. In addition, the max memory usage is kept track of using a high watermark for both the threads and the isolates. Isolate high watermark information is updated when a thread exits the isolate. The isolate high watermark consists of the sum of all thread high watermarks (including the high watermark of the exiting thread). High watermark information for both threads and isolates is now visible in the isolate view in the Observatory.
BUG=
R=johnmccutchan@google.com
Review-Url: https://codereview.chromium.org/2609253002 .
Added methods to surface number of zone and scoped handles in each isolate. These values are displayed in the isolate view page in the Observatory. These handle counts for the native IO isolate will be surfaced in another CL.
BUG=
R=asiva@google.com
Review-Url: https://codereview.chromium.org/2601153002 .
Added tracking of memory usage inside of threads. In addition, the max memory usage is kept track of using a high watermark for both the threads and the isolates. Isolate high watermark information is updated when a thread exits the isolate. The isolate high watermark consists of the sum of all thread high watermarks (including the high watermark of the exiting thread). High watermark information for both threads and isolates is now visible in the isolate view in the Observatory.
BUG=
R=asiva@google.com
Review-Url: https://codereview.chromium.org/2608463002 .
- Adjust fingerprints to be independent of the library's private key, which varies with load order.
- Use usage_counter in AOT inlining decisions if JIT feedback is available.
- Reduce inlining in cold functions.
dart2js product aot snapshot 15841351 -> 14436273 (-8.86%)
R=fschneider@google.com
Review-Url: https://codereview.chromium.org/2562693003 .
- Refactor the JumpToExceptionHandle code so that it is now built from
two pieces: JumpToFrame and RunExceptionHandler.
- Refactor the Simulator::Longjmp() code so that it is no longer
exception-specific. Instead it uses the RunExceptionHandler stub.
This makes it so that the JumpToFrame stub and Simulator::JumpToFrame
have the same semantics. This will make it easier to land the Rewind
changes I am working on.
There are some oddities for dbc.
BUG=
R=johnmccutchan@google.com
Review URL: https://codereview.chromium.org/2503653002 .
- fixed an inadvertant flip in the safepoint check in this cl
https://github.com/dart-lang/sdk/commit/e72c1fb47
- return (IsMutatorThread() ||
- (isolate_ != NULL && !isolate_->thread_registry()->AtSafepoint()));
+ return (IsMutatorThread() || IsAtSafepoint());
- increase the scope of CanCollectGarbage in Heap::AllocateOld to also
account for the tasks lock as checking for tasks inside a safepoint
scope can lead to deadlocks
- fix an aggressive assertion in compiler for expected errors being only
LanguageErrors to allowing UnhandledExceptions (OOM, stack overflows etc.)
- fix an aggressive assert in exception handler (handler pc can be 0 even in the mutator thread.
- workaround issue 27413 in PageSpace::CanIncreaseCapacityInWords
BUG=27380
R=fschneider@google.com
Review URL: https://codereview.chromium.org/2363823002 .
Martin Kustermann